It is known to make composite textile products by lining or laminating fabrics associated with membrane layers that function as a barrier against liquids, in order to obtain protective garments or other products that are impermeable from the outside to the inside, but transpirant, that is, they allow fluids to pass from the inside to the outside.
One known textile product is the three-layer type and comprises a first external layer, a second intermediate layer and a third internal layer. The first external layer is a layer of textile material of various type, which may or may not comprise a textile structure of various type. The second intermediate layer is a sheet or film of polymeric material which functions as a barrier against liquids from outside to inside and as a membrane that is transpirant to fluids from inside to outside. The third internal layer is generally made by means of a complex textile structure, for example fleece or pile, meaning a fabric worked in different ways, by shaping, incisions, reliefs, or a fibrous or filament structure, including woven or non-woven materials, knitted fabrics, brushed, teaseled, carded materials or other.
Normally, the three-layer textile product is supplied cut into panels which, to make the impermeable garments or other products in question, are joined to each other along suitably made joining lines, so that they are comfortable for the user. The textile products are in fact also called “soft-shell”, because they must have flexible and soft joins, and constitute durable and resistant materials on the outside, but soft inside, to provide comfort to the touch and wearability.
The joins between the panels of three-layer fabric in question are made by a first stitching operation, using needles, or an ultrasound join or other, along joining edges, and a subsequent taping operation along the sewn edges, that is, appliqués of sealing and impermeabilizing tapes applied hot on the side intended to face the inside during use.
However, the joining step in itself would not guarantee the impermeability of the join, due to the effect of the capillarity of the liquids that penetrate into the fabrics, in particular passing from the first external layer to the third internal layer in correspondence with the stitching zone. Indeed, the individual threads used to make the textile material are formed by filaments which create unsealable interstices between them, through which the liquids are absorbed due to capillarity or seepage.
To obviate this problem it is known, for example from the patent U.S. Pat. No. 7,117,545, to carry out an operation, upstream of the first stitching operation, of preparing the fabric by mechanically removing the material which constitutes the internal layer along the edges of the panels which will then be joined, so as to reach and expose the second intermediate impermeable layer which functions as a barrier: this operation is known as fleshing or shaving.
Subsequently, by means of stitching, ultrasound joining, high frequency joining or other, the join is made, taking care to leave visible, at the sides of the joining line, a portion of the second intermediate barrier layer; and finally, the sealing tape is applied astride the joining line directly on the portion of the second intermediate layer left free following the fleshing or shaving Impermeability is obtained thanks to the fact that the sealing tape adheres directly to the second intermediate layer that functions as a barrier.
The preparatory operation of fleshing or shaving is complex and slow because it is necessary to act with extreme skill, since on the one hand it is easy to damage the second intermediate layer below the portion of third layer being removed, and on the other hand it is possible that residues of unremoved third layer may remain, in both cases with negative effects on the impermeabilization.
Furthermore, the preparatory operation, which is carried out using suitable shaving machines, fleshing machines or sanding machines, produces a great quantity of removed material which is dispersed, in the form of powder or light particulate, into the surrounding environment, to the detriment of the operators present.
Other machines that apply a sealing tape are known from US 2003/010439, US 2006/000546 and EP 2.098.630.
Purpose of the present invention is to perfect a machine to make an impermeable join on three-layer or two-layer impermeable fabrics which allows to make the impermeable join quickly, safely and reliably, without having recourse to preparatory operations such as mechanical fleshing, at the same time keeping the impermeability and the minimum thickness of the fabric, which is comfortable, pleasant to the touch and to the eye, and pleasant to wear.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.